You’ve invested in insulation upgrades, installed double glazing, and perhaps even added solar panels—yet your Energy Performance Certificate (EPC) still shows a disappointing D or E rating. How is this possible?

The problem might not be your property’s actual efficiency but rather a case of unrecorded retrofitting—a growing issue we at EPCrate call the “EPC Black Hole.”

What is the EPC Black Hole?

The EPC Black Hole refers to properties where energy-saving improvements have been made, but these upgrades are unverified, undocumented, or invisible to the EPC assessment process. Without proper evidence, assessors are forced to use default assumptions, which often undervalue the property’s true efficiency.

Common Retrofit Improvements That Fall Into the EPC Black Hole

  1. Cavity Wall Insulation Without Certification
    If cavity insulation has been installed but lacks a CIGA (Cavity Insulation Guarantee Agency) certificate or documentation, assessors may ignore it.

  2. Floor Insulation Works
    Retrofits like underfloor insulation are hard to verify unless photographic evidence or invoices are provided.

  3. Roof & Loft Insulation Hidden Under Boarding
    Without visible access or installation records, upgraded insulation in boarded lofts may not be counted.

  4. Upgraded Double or Triple Glazing with Unavailable Specifications
    Replaced windows lacking manufacturer details (e.g., U-values, installation date) might be treated as older, less efficient units.

  5. Solar PV Systems Not Recorded on EPC Database
    Solar installations not registered properly or lacking MCS certificates may be ignored in the EPC calculation.

  6. Heating System Upgrades (e.g., New Boilers, Heat Pumps)
    If the make, model, and efficiency of the heating appliance aren’t documented, assessors are forced to use generic or default figures.

Why Default EPC Assumptions Can Drag Down Ratings

EPC software works on a “known data or default value” basis:

  • If an assessor can’t see or verify an improvement, the system defaults to a conservative estimate.

  • This results in properties with significant efficiency upgrades scoring similar to untouched, older homes.

How to Escape the EPC Black Hole

  1. Gather Retrofitting Documentation

    • Installation certificates (e.g., CIGA, FENSA, MCS).

    • Invoices from contractors specifying works done.

    • Manufacturer specifications for heating systems, glazing, and insulation products.

  2. Provide Photographic Evidence

    • Photos showing insulation materials being installed.

    • Clear images of product labels on windows, boilers, or insulation boards.

  3. Access Difficult Areas Before Assessment
    Ensure boarded lofts, concealed cavity walls, or underfloor sections are made accessible or documentation is provided.

  4. Work with Assessors Experienced in Non-Standard Evidence
    EPCrate’s assessors know how to input non-conventional data correctly, avoiding unnecessary default penalties.

Consequences of Ignoring the EPC Black Hole

  • MEES Non-Compliance Risks: Landlords could face legal issues if EPC ratings fail to meet required standards (E or C under future regulations).

  • Reduced Property Value: EPC scores are increasingly influencing property valuations.

  • Missed Funding Opportunities: Grants and green loans often require proof of high EPC ratings.

Book a Documentation-Aware EPC Assessment with EPCrate

If your property’s energy upgrades aren’t reflected in its EPC, you’re stuck in the EPC Black Hole.
EPCrate can help ensure that retrofitting efforts are properly documented and credited in your next assessment.

Book an assessment now or check our pricing plans for documentation-review services.